Long Clinical Consultation

Approach to Difficulty Walking

Charcot Arthropathy • Diabetic Foot • MRCP (UK) PACES

A structured PACES approach to a patient presenting with difficulty walking due to a swollen neuropathic ankle. Learn how to recognise Charcot arthropathy, distinguish it from osteomyelitis, assess diabetic complications and explain management confidently.

10 min read Long Clinical Consultation Very High Yield

At a Glance

Presentation Difficulty walking with a swollen ankle
Likely Diagnosis Charcot Arthropathy
Underlying Cause Diabetic Peripheral Neuropathy
Must Not Miss Osteomyelitis
Classic Sign Warm, swollen, painless unstable ankle
Treatment Immobilisation, Off-loading and MDT Foot Care

Red Flags

Acute hot swollen foot Ulcer or discharge Fever or systemic illness Rapidly progressive deformity Suspected osteomyelitis Urgent diabetic foot referral

PACES Approach

① Characterise walking difficulty ② Assess the swollen ankle ③ Look for neuropathy & diabetic complications ④ Confirm Charcot Arthropathy ⑤ Explain foot protection & long-term care

Overview

Charcot arthropathy is a destructive neuropathic joint disease, most commonly caused by diabetic peripheral neuropathy. Patients typically present with difficulty walking, a swollen warm foot or ankle, and surprisingly little pain despite significant joint destruction. In PACES, candidates should recognise the characteristic clinical features, distinguish Charcot arthropathy from osteomyelitis and vascular disease, assess diabetic complications, and explain the importance of early immobilisation, off-loading, and multidisciplinary diabetic foot care. :contentReference[oaicite:0]{index=0}

Structured History

  • Difficulty walking – onset and progression
  • Swelling, redness or deformity of the foot/ankle
  • Pain severity (often surprisingly mild)
  • Previous trauma or minor injury
  • History of foot ulcers or previous amputations
  • Duration and control of diabetes (HbA1c)
  • Symptoms of peripheral neuropathy
  • Features of peripheral arterial disease (claudication/rest pain)
  • Fever, discharge or systemic symptoms suggesting infection
  • Previous Charcot foot or diabetic foot clinic follow-up

Examination

  • Observe gait and weight-bearing ability
  • Warm, swollen, erythematous foot or ankle
  • Foot deformity or rocker-bottom appearance
  • Inspect for ulcers, callosities or infection
  • Palpate for local warmth and joint instability
  • Peripheral pulses (DP & PT)
  • 10-g monofilament sensation
  • Vibration sense using 128-Hz tuning fork
  • Joint position sense and ankle reflexes
  • Complete vascular and neurological examination

Differential Diagnosis

Osteomyelitis Cellulitis Septic arthritis Gout Ankle fracture Peripheral arterial disease Deep vein thrombosis Osteoarthritis

Investigations

  • Weight-bearing foot and ankle X-rays
  • MRI foot (early Charcot or osteomyelitis)
  • Inflammatory markers (CRP, ESR)
  • FBC and blood cultures if infection suspected
  • HbA1c and glucose profile
  • Ulcer swab or deep tissue culture if indicated
  • Arterial Doppler studies when vascular disease suspected
  • Bone biopsy only if diagnosis remains uncertain

Diagnosis

Charcot Arthropathy (Neuropathic Osteoarthropathy)

The diagnosis is suggested by a warm, swollen, relatively painless foot or ankle in a patient with diabetic peripheral neuropathy. Early recognition is essential to prevent progressive deformity, ulceration and amputation.

Management

Acute Management Immediate immobilisation and complete off-loading
Definitive Care Multidisciplinary diabetic foot team with optimisation of diabetes
Long-term Goals Prevent ulceration, deformity and lower-limb amputation

Explaining to the Patient

"Your ankle has become damaged because the nerves supplying your foot have lost sensation. This means repeated minor injuries may occur without being noticed, leading to weakening of the bones and joints. The most important treatment is protecting the foot with a cast or special boot, avoiding weight-bearing until healing occurs, and carefully controlling your diabetes to reduce future complications."

Examiner's Corner

What are your clinical findings?
  • Warm, swollen, erythematous foot and ankle
  • Minimal pain despite marked deformity
  • Evidence of diabetic peripheral neuropathy
  • Joint instability with bony deformity
  • Possible rocker-bottom foot
  • Peripheral pulses should be assessed
  • Look carefully for ulcers or infection
Why does Charcot Arthropathy occur?

Loss of protective sensation due to peripheral neuropathy allows repeated minor trauma to occur unnoticed. Continued weight-bearing results in progressive bone destruction, fractures, joint collapse and severe foot deformity.

Common Viva Questions
  • What causes Charcot Arthropathy?
  • How do you differentiate it from osteomyelitis?
  • What investigations would you request?
  • Why is MRI useful?
  • What is the role of off-loading?
  • When is surgery indicated?
  • How would you counsel this patient?
Complications
Foot ulceration Osteomyelitis Foot deformity Recurrent infection Fractures Amputation

Pathfinder Pearls

Think Charcot in every warm diabetic foot Pain is often surprisingly mild Always examine both feet Assess neuropathy before vascular disease Exclude osteomyelitis early MRI detects early disease Off-loading is the cornerstone of treatment Refer to the multidisciplinary diabetic foot team

Common Pitfalls

  • Assuming every hot swollen diabetic foot is cellulitis.
  • Failing to perform a full neurological examination.
  • Ignoring peripheral vascular assessment.
  • Missing an underlying foot ulcer.
  • Allowing continued weight-bearing despite suspected Charcot Arthropathy.
  • Not considering osteomyelitis.
  • Delaying referral to the diabetic foot multidisciplinary team.

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